Spinal fusion devices, systems and methods

ABSTRACT

According to some embodiments, a method of inserting a lateral implant within an intervertebral space defined between an upper vertebral member and a lower vertebral member includes creating a lateral passage through a subject in order to provide minimally invasive access to the intervertebral space, at least partially clearing out native tissue of the subject within and/or near the intervertebral space, positioning a base plate within the intervertebral space, wherein the base plate comprise an upper base plate and a lower base plate and advancing an implant between the upper base plate and the lower base plate so that the implant is urged into the intervertebral space and the upper vertebral member is distracted relative to the lower vertebral member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/210,056, filed Mar. 13, 2014, which claims thepriority benefit under 35 U.S.C. § 119(e) of U.S. ProvisionalApplication No. 61/786,160, filed Mar. 14, 2013, the entireties of bothof which are hereby incorporated by reference herein.

BACKGROUND Field

This application relates generally to devices, systems and methods forthe treatment of the spine, and more specifically, to spinal implantsand related tools, systems and methods.

Description of the Related Art

Surgical approaches to the intervertebral space are utilized for avariety of indications and purposes, such as, for example, biopsy (e.g.,for evaluation of possible infection, other pathology, etc.), discectomy(e.g., for decompression of nerve roots, to prepare for subsequentfusion procedures, etc.), disc height restoration or deformitycorrection, disc replacement or repair (e.g., annular repair),discogram, gene therapy and/or other procedures or treatments.

Various approaches are currently used to access the interbody orintervertebral space of a patient's thoracic, lumbar and sacral spine.These include anterior approaches (ALIF) (e.g., open, mini-openretroperitoneal, etc.), lateral approaches (e.g., costotranversectomy,extreme lateral, etc.), posterolateral approaches (e.g., posteriorlumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion(TLIF), etc.) and axial approaches (e.g., axial lumbar interbodyfusion). Further, many minimally invasive and percutaneous approachesrely on radiographic landmarks with or without direct view to access atargeted interbody space. In addition, many, if not all, of thesecurrently used approaches require violation of the disc annulus toaccess the disc space.

Fusion surgery of the thoracic, lumbar and sacral spine is oftenperformed for a variety of indications, including degenerative jointdisease, deformity, instability and/or the like. Typically, traditionalfusion approaches involve relatively large, open incisions performedunder direct vision. Minimally invasive surgical techniques andcorresponding surgical implants have become more popular in an attemptto reduce morbidity and generally improve outcomes. Multiple variationsof percutaneous systems (e.g., pedicle screw and rod systems, facetscrew systems, etc.) have been developed. Such systems can allow forinstrumentation placement with fluoroscopic guidance (e.g., usingradiographically recognizable body landmarks) and/or other imagingtechnologies. Current fusion techniques, including those that utilizeopen and minimally invasive approaches, often require directvisualization. However, such techniques typically involve traversingspaces that are occupied by neural elements. Thus, these neural elementsneed to be retracted or otherwise moved during the execution of spinalprocedures that precede implantation (e.g., annulotomy, discectomy, discspace and/or vertebral endplate preparation, etc.). Retraction ofsensitive neural elements can also be required during the delivery of animplant to the spine.

These approaches typically require contact and retraction of nerve rootsand/or sensitive visceral organs, blood vessels and/or other sensitiveportions of the anatomy. Contact and retraction of these structures canplace them at risk, thereby increasing the likelihood of complicationsand damage to a patient. Accordingly, a need exists for improvedapproaches for spinal fusion and/or access to intervertebral spaces.

SUMMARY

According to some embodiments, a method of inserting a lateral implantwithin an intervertebral space defined between an upper vertebral memberand a lower vertebral member includes creating a lateral passage througha subject in order to provide minimally invasive access to theintervertebral space, at least partially clearing out native tissue ofthe subject within and/or near the intervertebral space, positioning abase plate within the intervertebral space, wherein the base platecomprise an upper base plate and a lower base plate and advancing animplant between the upper base plate and the lower base plate so thatthe implant is urged into the intervertebral space and the uppervertebral member is distracted relative to the lower vertebral member.

According to some embodiments, advancing an implant between the upperand lower base plates comprises using a mechanical device (e.g., athreaded-system using a rotable handle to advance a rod or otheractuator, manual or mechanically-assisted device, etc.). In someembodiments, the implant comprises at least one groove and at least oneof the upper base plate member and the lower base plate member comprisesat least one protruding feature, the at least one groove beingconfigured to align and move relative to the at least one protrudingfeature. In some embodiments, the implant is delivered through the baseplate using a rail or other alignment system. In some embodiments, theimplant comprises at least one of PEEK, titanium and/or the like. Insome embodiments, the base plate comprises titanium, stainless steel oranother medically-acceptable metal or alloy.

According to some embodiments, the method further includes securing atleast one screw (e.g., 1, 2, 3, 4, more than 4, etc.) through an openingof the implant after the implant has been properly secured within theintervertebral space. In one embodiment, the screw also passes throughat least a portion of the upper or lower base plate member and/or theupper or lower vertebra.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentapplication are described with reference to drawings of certainembodiments, which are intended to illustrate, but not to limit, thepresent inventions. It is to be understood that these drawings are forthe purpose of illustrating the various concepts disclosed herein andmay not be to scale.

FIG. 1 schematically illustrates one embodiment of a spinal implantsystem with the implant not positioned within the target intervertebralspace;

FIG. 2 illustrates the system of FIG. 1 with the implant positionedbetween the base plate members and implanted within the intervertebralspace;

FIGS. 3A and 3B illustrate various views of a base plate of an implantsystem according to one embodiment;

FIG. 4 illustrates a side view of a spinal implant system according toone embodiment;

FIGS. 5A-5C illustrate various views of one embodiment of a base platefor use in a spinal implant system;

FIGS. 6A and 6B illustrate various views of one embodiment of an implantconfigured for use in a spinal implant system;

FIG. 7A illustrates one embodiment of a base plate configured for use ina spinal implant system;

FIG. 7B illustrates one embodiment of an implant configured to be usedtogether with the base plate of FIG. 7A;

FIGS. 8A-8C illustrate various time-sequential side views during aspinal implant procedure according to one embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A variety of examples described below illustrate various configurationsthat may be employed to achieve desired improvements. The particularembodiments and examples are only illustrative and not intended in anyway to restrict the general concepts presented herein and the variousaspects and features of such concepts.

According to some embodiments, the present application discloses variousdevices, systems and methods for accessing the intervertebral orinterbody space of a patient's spine and/or performing certainprocedures related to spinal fusion using minimally invasive surgery(MIS) techniques. As discussed in greater detail herein, theintervertebral or interbody space of the targeted portion of thepatient's spine is accessed and/or treated minimally invasively using,at least in some embodiments, a lateral approach. The terms“intervertebral space” and “interbody space” are used interchangeablyherein, and generally refer to the space, gap or region between adjacentvertebral members. By way of example, as illustrated in FIG. 1, theintervertebral space 14 between adjacent vertebrae 10, 12 can beaccessed using one or more lateral openings or passages createdlaterally through the subject's anatomy (e.g., using one or more accessdevice, such as, retractors, dilators, etc.). In some embodiments, suchopenings or passages are created, accessed and/or otherwise use usingMIS techniques or procedures.

FIG. 1 schematically illustrates one embodiment of a spinal fusion orstabilization system 50. As shown, the system 50 can include upper andlower plates 300 or other members that are positioned along theendplates of the upper and lower vertebral members 10, 12. In someembodiments, the plates 300 generally extend across the entire orsubstantially the entire width of the vertebrae 10, 12. In someembodiments, the plates 300 are the same length or substantially thesame length as the spinal implant 200 that will be delivered between theplates 300 and into the intervertebral space 14. For example, the plates300 and/or the implant 200 can be approximately 40 to 60 mm long (e.g.,40, 45, 50, 55, 60 mm, lengths between the foregoing ranges, etc.). Inother embodiments, however, the length of the implant is greater than 60mm or less than 40 mm, as desired or required.

In some embodiments, once the plates have been properly positionedwithin the target intervertebral space 14, the implant 200 can bedelivered (e.g., laterally) between the upper and lower plates or othermembers 300. The delivery of the implant 200 between the plates 300 canbe performed with or without the use of a mechanical delivery tool(e.g., by using a threaded delivery device or other device providing formechanical advantage, etc.). Regardless of the exact manner in which theimplant 200 is advanced into the intervertebral space 14, the upper andlower plates 300 can provide one or more advantages or benefits. Forexample, the use of the plates 300 can help distribute forces andmoments along a larger surface area. This is schematically and generallyillustrated by the force distribution diagram F in FIG. 2. Accordingly,the likelihood of potentially damaging localized forces, moments and/orother stresses on a particular portion or area of the adjacent vertebrae10, 12 can be reduced or eliminated.

Further, in some embodiments, the use of the upper and lower plates 300can facilitate the delivery of the implant 200 within the targetinterbody space with greater ease and less resistance. As a result, theendplates and other portions of the adjacent vertebrae 10, 12 can beprotected against shearing, fractures and/or other damage. This can beespecially important when the implant 100 causes distraction (e.g.,separation or opening) of a collapsed or partially collapsed interbodyspace 14, as represented by the arrows 16 in FIG. 2.

As discussed herein, one or both sides of the upper and/or lower platescan include spikes, teeth, other protruding members and/or otherengagement features. For example, if such engagement features arepositioned along the top of the upper plate or the bottom of the lowerplate, the engagement features can be advanced into the adjacentendplate(s) as the implant 200 is moved between the plates 300. This canhelp secure the plates to the adjacent vertebrae 10, 12. In someembodiments, engagement features can be positioned along the oppositesurfaces of the plates (e.g., along the bottom of the upper plate and/oralong the top of the lower plate). Such engagement features can helpprevent or reduce the likelihood of relative movement between theimplant 200 and the plates 300 following implantation. As discuss ingreater detail herein, the plates can include one or more otherfeatures, such as, for example, rails or guiding members (e.g., toassist in moving the implant more easily and more predictably betweenthe plates), tabs or other portions configured to receive one or morescrews or other fasteners (e.g., to further secure the system 100 to thespine after delivery into the intervertebral space) and/or the like.

FIGS. 3A and 3B illustrate different views of one embodiment of plates(e.g., base plates) 300 configured for use in a lateral spinal fusionsystem. As shown, the base plates 300 can include upper and lower plates310, 314. The base plates 300 can be shaped, sized and configured tospan across an entire width of the subject's vertebrae 10, 12. In otherembodiments, the base plates 300 extend beyond one or more side of thevertebral periphery or do not extend to the lateral edge of thevertebrae (e.g., are short by a certain clearance distance from one ormore lateral edges of the vertebrae). As shown in FIG. 3A, the platemembers 310, 314 can include one or more protruding members 320 thatextend toward each other (e.g., toward the intervertebral space). Suchprotruding members can be fixed or movable. For example, in someembodiments, the protruding members 320 are deployable (e.g., before,during or after advancement of an implant between the base plates 300).

With continued reference to FIG. 3A, a system can include a guidingassembly 500 that can be strategically positioned along one of thelateral ends of the targeted intervertebral space. The guiding assembly500 can include an alignment device 510 that may comprise one or morealignment components 514, 516. Regardless of its exact configuration anddesign, the alignment device can advantageously permit a surgeon orother practitioner to accurately position the guiding assembly 500 forthe subsequent delivery of an implant therethrough and between the baseplates 300. As shown in FIG. 3A, the alignment components 514, 516and/or one or more other portions or components of the assembly caninclude a flange or other abutment or securement portion 518. Such aflange 518 can be fixedly or movable positioned along the adjacentvertebrae 10, 12 of the subject to ensure proper alignment into thetargeted intervertebral space.

As illustrated in FIG. 4, an implant 200 can be delivered between thebase plates 300 and into the intervertebral space using a mechanicaladvancement device. Therefore, in some embodiments, the guiding assembly500 can advantageously comprise a mechanical advancement device orfeature. For example, in FIG. 4, the guiding assembly comprises athreaded delivery portion that is configured to advance an implant 200between the base plate members 310, 314 by turning a rotable handle orother advancement tool. As a user rotates the handle 520, a rod 522 orother actuator is moved forwardly (e.g., distally) in the direction ofthe implant 200. The implant 200 can be directly or indirectly coupledto the actuator 522 via one or more coupling or other detachableconnections 526, as desired or required. As the rod is advanceddistally, the implant (e.g., lateral cage) can be guided between thebase plate members 310, 314 and into the intervertebral space.Consequently, the base plate members 310, 314 separate and are urgedtoward the adjacent endplates of the vertebrae. In some embodiments, asillustrated schematically in FIG. 4, the implant can include a taper(e.g., bullet design) along its distal end to facilitate initial entryand subsequent distraction and separation of the base plate 300.

With continued reference to FIG. 4, the guiding assembly 500 can includeone or more structures 510 that ensure that the implant stays within theguiding assembly 500 and aligned with the intervertebral space duringadvancement between the plates. Such structure 510 can, for example,help reduce any deflection or misdirection of the implant's leading endduring distal delivery to the intervertebral space, especially whenrelatively high forces are being exerted on the implant (e.g., that mayotherwise cause the implant to move our of alignment with the baseplates). In some embodiments, the implant 200, the base plates 300and/or any other portion of the system can include rails or otheralignment features that further help maintain a proper alignment of theimplant during advancement between a subject's vertebrae.

FIGS. 5A-5C illustrate various views of another system comprising baseplates 300 for receiving a spinal implant. As shown, an alignment device510′ can be positioned relative to one or more of the adjacent vertebrae10, 12 more securely. For example, one or more screws S or otherfasteners can be used to secure one or more portions of the alignmentdevice to the upper and/or lower vertebral members of the subject. Insome embodiments, the alignment devices 510′ comprise one or moreflanges or plates P through which the screws S or other fasteners can beplaced. Once the alignment device 510′ has been secured to the subject,the implant can be delivered between the base plate members 310, 314.The alignment device 510′, base plate 300 and/or other portions of thesystem can be left in place after the implant has been secured betweenthe subject's vertebrae. In other embodiments, however, one or morecomponents of the system (e.g., base plate 300, screws, etc.) can beleft in place after implantation, and in some instances, may helpreinforce or otherwise benefit the treated area.

One embodiment of an implant 200 that can be used with the spinalsystems disclosed herein is illustrated in FIGS. 6A and 6B. As bestshown in the top view of FIG. 6B, the implant 200 can include one ormore open regions or chambers 210 for holding a grafting material. Inaddition, the implant can include one or more grooves 220 or otherrecesses along its anterior and/or posterior walls. In some embodiments,such grooves 220 or other features can align and mate with correspondingrails, protrusions or features of the base plate 300. Accordingly, thegrooves, rails and/or other features can help safely, accurately andpredictably move the implant 200 into the target intervertebral space(e.g., between adjacent base plate members).

In some embodiments, the implant comprises PEEK, titanium or otheracceptable materials. For example, in some embodiments, the implant 200comprises a metal edge plate 226 through which one or more screws (notshown in FIGS. 6A and 6B) can be subsequently delivered to secure theimplant 200 to one or more vertebrae. In some arrangements, the plate226, which can be positioned along the proximal end of the implant 200,comprises titanium or other acceptable metal or alloy.

FIG. 7A illustrates a side view of one embodiment of a base plate 300comprising upper and lower plate members 310, 314. As shown, the baseplate members 310, 314 can include one or more protruding members 320.Such protruding members 320 can include tabs, bumps, spikes, othersharp, smooth and/or rounded features or members and/or the like. Insome embodiments, the protruding members 310, 314 can be fixed (e.g.,non-movable, non-deployable, etc.) and/or movable (e.g., selectivelyretractable, deployable, etc.). For example, in some embodiments, theprotruding members 320 of the upper and/or lower plate members 310, 314are deployable using a mechanical connection, a temperature changeand/or using some other mechanism of action, device or method.

FIG. 7B illustrates a top view of one embodiment of an implant 200 thatis configured to be used with the base plate 300 of FIG. 7A.Specifically, as shown, the implant 200 can include one or more grooves,holes, recesses or other openings 240 that are shaped, sized andotherwise configured to receive corresponding protruding members 320 ofthe base plate 300. In some embodiments, the protruding members 320′ ofthe base plate 300 include a curved leading edge in order to permit thegroove 240 of the implant 200 to only temporarily engage the member 320′as the implant is advanced into the target intervertebral space. Thus,the protruding members can sequentially engage and disengage a groove onthe implant (e.g., in a ratcheting manner). In some embodiments, theimplant can only be permitted to be advanced in one direction (e.g.,distally). Such an embodiment can be helpful when using base plates 300that have fixed protruding members 320. In embodiments comprisingdeployable protruding members, the need for such ratcheting system(e.g., that permits movement in at least one direction) may not beneeded, as the protruding members 320 can be selectively deployed onlywhen the implant is properly positioned between the base plate members.

In some embodiments, the use of protruding members and correspondinggrooves or other recesses can help with guiding an implant 200 betweenadjacent base plate members (e.g. during delivery). Such embodiments canalso assist in securely maintaining the implant in its implantedpositioned following delivery of the implant in the targetintervertebral space.

As illustrated schematically in FIGS. 8A-8C, a lateral implant device inaccordance with the various embodiments disclosed herein, can bedelivered to the target intervertebral space minimally invasively (e.g.,through one or more tissue dilations or other openings). As discussed ingreater detail herein, once the base plate 300 has been properlypositioned between the subject's vertebrae 10, 12, a guiding assembly500 can be positioned through a dilator or other access opening and ingeneral alignment with the targeted intervertebral space. The implantcan be advanced using a mechanical device (as illustrated in FIG. 8A)and/or using some other method or device. Further, the implant and baseplate can include one or more features or members (e.g., rails, grooves,etc.) to assist in accurately moving the implant in the desiredanatomical location of the subject's spine. Once the implant has beenadvanced between the base plate members 310, 314 and properly within theintervertebral space, the guiding assembly 500 can be removed.

With reference to FIG. 8B, in some embodiments, a screwdriver or othermechanical device 600 can be delivered through a dilator, cannula orother access device C to advance one or more screws S or other fastenersthrough corresponding openings along the proximal end of the implant200. Therefore, the position of the implant 200 relative to thesubject's spine can be safely and firmly maintained, as shown in FIG.8C. The screws S can be routed through the implant, the base plateand/or the vertebra, as desired or required. However, in otherembodiments, the use of screws S or other fasteners is not needed orrequired to maintain the implanted implant between the base platemembers and the adjacent vertebrae. In some embodiments, a total of fourfixation screws are positioned through the proximal end of the implantedimplant (e.g., two above and two below). In other embodiments, more orfewer screws or other fasteners can be used, as desired or required.

In order to remove disk material, cartilage, endplate or other vertebraltissue and/or native tissue of a subject during an implantationprocedure, a surgeon or other practitioner can use any of the rasping orother tissue cutting devices and methods disclosed in U.S. patentapplication Ser. No. 13/422,816, titled TRANSPEDICULAR ACCESS TOINTERVERTEBRAL SPACES AND RELATED SPINAL FUSION SYSTEMS AND METHODS,filed Mar. 16, 2012 and published as U.S. Publ. No. 2012/0265250 on Oct.18, 2012, and U.S. Provisional Patent Application No. 61/783,839, titledDEVICES AND METHODS FOR TRANSPEDICULAR STABILIZATION OF THE SPINE andfiled on Mar. 14, 2013, the entireties of both of which are herebyincorporated by reference herein and made a part of the presentapplication.

To assist in the description of the disclosed embodiments, words such asupward, upper, bottom, downward, lower, rear, front, vertical,horizontal, upstream, downstream have been used above to describedifferent embodiments and/or the accompanying figures. It will beappreciated, however, that the different embodiments, whetherillustrated or not, can be located and oriented in a variety of desiredpositions.

Although the subject matter provided in this application has beendisclosed in the context of certain specific embodiments and examples,it will be understood by those skilled in the art that the inventionsdisclosed in this application extend beyond the specifically disclosedembodiments to other alternative embodiments and/or uses of the subjectmatter disclosed herein and obvious modifications and equivalentsthereof. In addition, while a number of variations of the inventionshave been shown and described in detail, other modifications, which arewithin the scope of these inventions, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combinations or subcombinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the inventions disclosed herein. Accordingly, it should beunderstood that various features and aspects of the disclosedembodiments can be combine with or substituted for one another in orderto form varying modes of the disclosed inventions. Thus, it is intendedthat the scope of the subject matter provided in the present applicationshould not be limited by the particular disclosed embodiments describedabove, but should be determined only by a fair reading of the claimsthat follow.

1-7. (canceled)
 8. A spinal fusion system comprising: an upper plate; alower plate; wherein the upper plate and the lower plate are configuredto be positioned within an intervertebral space of a subject; and animplant configured to be advanced between the upper plate and the lowerplate, wherein advancing the implant between the upper plate and thelower plate is configured to separate the upper plate relative to thelower plate along an entire length of the implant; wherein at least oneof the upper plate and the lower plate comprises a plurality of movableprotruding members, wherein the movable protruding members areconfigured to be deployed when the implant is advanced between the upperplate and the lower plate.
 9. The system of claim 8, wherein the movableprotruding members comprise spikes or other sharp features or members.10. The system of claim 8, wherein the system comprises alignmentfeatures to assist in alignment of the upper and lower plates relativeto the implant.
 11. The system of claim 10, wherein the alignmentfeatures comprise one or more rails and one or more grooves, wherein theone or more grooves are configured to mate with the one or more rails.12. The system of claim 8, wherein the implant comprises at least one ofPEEK and titanium.
 13. The system of claim 8, further comprising atleast one screw or other fastener, wherein the at least one screw orother fastener is configured to further secure the system to a subject'sspine.
 14. The system of claim 8, wherein the implant comprises at leastone chamber configured to hold grafting material.
 15. A spinal fusionsystem comprising: an upper base member; a lower base member; whereinthe upper base member and the lower plate are configured to bepositioned within an intervertebral space of a subject; and an implantconfigured to be advanced between the upper base member and the lowerbase member, wherein the implant is configured to move the upper basemember relative to the lower base member along an entire length of theimplant when the implant is advanced between the upper base member andthe lower base member; wherein at least one of the upper base member andthe lower base member comprises a plurality of protruding members,wherein the protruding members are configured to be deployed when theimplant is advanced between the upper base member and the lower basemember.
 16. The system of claim 15, wherein the protruding memberscomprise spikes or other sharp features or members.
 17. The system ofclaim 15, wherein the system comprises alignment features to assist inalignment of the upper and lower base members relative to the implant.18. The system of claim 17, wherein the alignment features comprise oneor more rails and one or more grooves, wherein the one or more groovesare configured to mate with the one or more rails.
 19. The system ofclaim 15, wherein the implant comprises at least one of PEEK andtitanium.
 20. The system of claim 15, further comprising at least onescrew or other fastener, wherein the at least one screw or otherfastener is configured to further secure the system to a subject'sspine.
 21. The system of claim 15, wherein the implant comprises atleast one chamber configured to hold grafting material.
 22. A spinalfusion system comprising: an upper base member; a lower base member; andan implant configured to be advanced between the upper base member andthe lower base member; wherein at least one of the upper base member andthe lower base member comprises a plurality of protruding members,wherein the protruding members are configured to be deployed when theimplant is advanced between the upper base member and the lower basemember.
 23. The system of claim 22, wherein the protruding memberscomprise spikes or other sharp features or members.
 24. The system ofclaim 22, wherein the system comprises alignment features to assist inalignment of the upper and lower base members relative to the implant.25. The system of claim 24, wherein the alignment features comprise oneor more rails and one or more grooves, wherein the one or more groovesare configured to mate with the one or more rails.
 26. The system ofclaim 22, wherein the implant comprises at least one of PEEK andtitanium.
 27. The system of claim 22, wherein the implant comprises atleast one chamber configured to hold grafting material.